A bar with a circular cross section having twodifferent diameters d and 2d is shown in the figure.The length of each segment of the bar is L/2, and themodulus of elasticity of the material is E. (a)...

A bar with a circular cross section having two
different diameters d and 2d is shown in the figure.
The length of each segment of the bar is L/2, and the
modulus of elasticity of the material is E.

(a) Obtain a formula for the strain energy U of the
bar due to the load P.
(b) Calculate the strain energy if the load
P = 27 kN, the length L = 600 mm, the
diameter d = 40 mm, and the material is
brass with E = 105 GPa.